This invention relates to a process for producing an alkylation reaction product from an alkylatable reactant and an olefin-acting reactant utilizing a fluid catalyst.
This invention also relates to a novel unitary vessel for producing an alkylation reaction product.
In one aspec, this invention relates to a process and apparatus, utilizing a fluid catalyst, for producing an isoparaffin-olefin reaction product which may be used as a motor fuel component. This process and apparatus herein disclosed provide a method for producing an isoparaffin olefin reaction product which possesses excellent anti-knock properties and which may be utilized to upgrade the octane level of unleaded motor fuels.
Alkylation processes are employed to create higher molecular weight compounds from lower molecular weight olefin-acting compounds and alkylatable compounds. For example, aromatic hydrocarbons may be alkylated with C.sub.10 -C.sub.20 olefins to produce higher molecular weight alkylaromatics which are useful as detergents. Aromatics may also be alkylated with C.sub.2 -C.sub.10 olefins to produce resin and plastics precursors such as ethylbenzenes, propylbenzenes, etc.
Among the most important products of fluid-catalyzed alkylation is the motor fuel alkylate produced in acid-catalyzed alkylation of C.sub.4 -C.sub.6 isoparaffins with C.sub.3 -C.sub.5 olefins. Generally, isobutane is alkylated with butene isomers or a mixture of propene and butenes utilizing hydrogen fluoride or sulfuric acid as a catalyst. The alkylate made in these processes generally has a fairly high octane rating which may be improved significantly by the addition of alkyl lead compounds. When such compounds as tetramethyl or tetraethyl lead are added to this alkylate product, its octane rating is high enough that it may be blended with other hydrocarbon components to create a motor fuel product having a desirably high octane rating. At present, it has been found desirable to ninimize the use of alkyl lead compounds to upgrade the octane rating of motor fuel alkylate. At the same time, motor fuel octane requirements remain high. There is thus, a present demand for motor fuel alkylate having a high enough octane rating without the addition of lead, or with very little lead, that it may be used economically as a motor fuel blending component. The alkylation processes and apparatus which are presently in use do not produce a product of sufficiently high octane to meet this demand in an economical manner. The process and apparatus herein disclosed provide a method for producing a higher octane alkylate needed to satisfy the demand for high octane unleaded motor fuels.
One of the problems associated with hydrogen halide-catalyzed alkylation processes, particularly those employing a hydrogen fluoride catalyst, has been the production of alkyl halides, which are undesirable in the final products of alkylation processes, but are troublesome to separate from more valuable reaction products. For example, in an isoparaffine-olefin alkylation process employing hydrogen fluoride catalyst, the reactants and catalyst are thoroughly mixed to form a reaction mixture. After the alkylation reaction has taken place, the product and unconsumed reactants form one phase and the catalyst forms a second phase. The alkyl halides created collect in the reaction products phase. Since these halides can be reacted with alkylatable reactant in the presence of high purity acid catalyst to form the desired products, it is desirable to eliminate them in this way, rather than by attempting to separate them from desirable products.